1. Field of the Invention
The present invention generally relates to an electronic calculator and a control method thereof, and more particularly, to an electronic calculator which selectively works in two different operation modes and a control method thereof.
2. Description of Related Art
Electronic calculators offer very convenient and fast calculation functions. Thus, electronic calculators are used in many aspects of our daily life, such as shopping, accounting, mathematical, or engineering applications, to carry out simple mathematical calculations or even calculations of complicated formulae.
Electronic calculators having different functions and specifications are usually designed according to the purposes and users of the electronic calculators. For example, regarding a personal electronic calculator, for the convenience of the user, operation information (for example, operation information stored by using the M+ key or the M− key) stored in the electronic calculator should be retained after the electronic calculator is turned off. On the other hand, regarding an electronic calculator used in an office or company or an electronic calculator for examination purpose, the previously stored operation information should be cleared every time when the electronic calculator is turned off, so as to ensure the security of the information or the fairness of an examination.
Even though a professional calculator manufacturer can manufacture aforementioned two different types of electronic calculators by using similar manufacturing processes, the calculator manufacturer still needs to change the design of the processing chips in the electronic calculators in order to allow the electronic calculators to have corresponding functions. Not only it is inconvenient to manufacture two different types of processing chips, but the management of the manufacturing cost and product inventory is made very troublesome.